Transmission slipping

[cspurli2]

My vehicle is a 2011 Subaru Impreza outback sport with 99k miles. I have owned it since December and put ~5k miles on it. The transmission feels like it is slipping, but there is no rhyme or reason to when it does it. Sometimes on my way to work it will slip alot, as in 3 out of the 5 gears (or 4 not sure how many my vehicle has) and other times it won't slip at all. I've changed the fluid and put stop slip in it. I took it to a transmission specialist mechanic and they said they couldn't feel it slip when they test drove it. Just wondering if theres something I can do or wait until the tranny blows and change it. 

[1 Lucky Texan]

can you take the mechanic for a drive and demonstrate the problem?

[heartless]

if it is an automatic, it is most likely a 4spd.

is it cold out when you notice the symptoms, or warmish?

tranny fluid should be checked with everything at operating temperature, the car running, and parked on a level surface. verify the fluid is at the correct level.

[lmdew]

Also take a good look at the half shafts CV Joints.  They are usually not an intermittent failure item, but worth a look.

[cspurli2]

10 hours ago, 1 Lucky Texan said:

can you take the mechanic for a drive and demonstrate the problem?

Bc it is only intermittent I haven't yet. They offered for me to do that. Next time it does it I will. 

[cspurli2]

8 hours ago, heartless said:

if it is an automatic, it is most likely a 4spd.

is it cold out when you notice the symptoms, or warmish?

tranny fluid should be checked with everything at operating temperature, the car running, and parked on a level surface. verify the fluid is at the correct level.

I checked the tranny fluid when hot and it was right between the markers where it should have been. And today it was 35° farenheit and on my 40 mile drive to work it only slipped 1 noticable time. 

[cspurli2]

22 minutes ago, lmdew said:

Also take a good look at the half shafts CV Joints.  They are usually not an intermittent failure item, but worth a look.

Alright. How do I verify that they are ok. Last time I checked they weren't leaking and the boots looked okay. 

[idosubaru]

Is 2011 still the EAT trans, that’s not a CVT right? 2011 is close to the introduction of CVT.  

1. Any check engine or flashing transmission lights?

2. Check for any outstanding recalls or TSBs for the trans shifting.

3. Check the transmission pan and make sure it’s not dented.  There’s very little clearance between the pan and internal uptake inlet.

4. has the car ever been wrecked?

5. This is a long shot and possible waste but if you can DIY it’s at least simple and not too $$$ relative to a shop or trans swap: change the trans fluid. If it’s a 4EAT try some amsoil. 

[cspurli2]

6 hours ago, idosubaru said:

Is 2011 still the EAT trans, that’s not a CVT right? 2011 is close to the introduction of CVT.  

1. Any check engine or flashing transmission lights?

2. Check for any outstanding recalls or TSBs for the trans shifting.

3. Check the transmission pan and make sure it’s not dented.  There’s very little clearance between the pan and internal uptake inlet.

4. has the car ever been wrecked?

5. This is a long shot and possible waste but if you can DIY it’s at least simple and not too $$$ relative to a shop or trans swap: change the trans fluid. If it’s a 4EAT try some amsoil. 

No engine lights, although it did have one for a vacuum leak when I got it but I cleared it when I got it and it hasn't come back. I'll check the tranny pan when I get home. The car does have a rebuilt title, I'm not sure the exact location not I do know it was at least somewhere up front because the paint on the bumper and one of the side fenders is slightly off. I'll try adding some and oil but there 1st time I changed out the fluid I put Lucas stop slip in it and the most recent time I tried trans x to no avail. Also this was the last year from my knowledge it was non cvt.

7 hours ago, lmdew said:

Also take a good look at the half shafts CV Joints.  They are usually not an intermittent failure item, but worth a look.

Alright. How do I verify that they are ok. Last time I checked they weren't leaking and the boots looked okay. 

[Numbchux]

Not much I can add here....

 

But FYI, a 2011 OBS will be a 4-speed 4EAT transmission. Last year in the Impreza chassis.

[idosubaru]

53 minutes ago, cspurli2 said:

The car does have a rebuilt title, I'm not sure the exact location not I do know it was at least somewhere up front because the paint on the bumper and one of the side fenders is slightly off.

Which side - drivers or passengers?

Follow all transmission lines from start to finish and ensure none are compressed, twisted, kinked around a bend, or otherwise compromised.  Generic hoses that aren't molded for OEM applications routinely kink.  They're predominantly centered under the radiator and drivers side fender area.

If they were busticated during the accident and puked fluid the transmission may have been compromised depending what transpired during and after the accident.  did they try to limp it home, drive it up on the truck...with leaking ATF lines...etc. 

[lmdew]

Halfshafts if the boots are good and there is NOT excessive play they should be good.

[1 Lucky Texan]

when it slips, the RPM and engine 'sound' increase with no speed increase?

[cspurli2]

It got hit on the passengers but I didn't even think to inspect the lines so I'll add that to the list. 

[cspurli2]

It depends, sometimes it will rev up very loud and then shift hard, but then other times it will kind of slip-catch-slip-catch with very little acceleration. I've noticed that it does it more if I either drive like a grandma meaning very slow on the revs, or if I mash it it will also slip more. But when I hold it at about 2700-3300 rpms it will do the slip catch thing and accelerate decently. I guess I'm just gonna have to ride it until it dies if I can't find what's wrong with your guys help. I appreciate it alot 

[cspurli2]

Alright thank you!

[Rampage]

33 minutes ago, cspurli2 said:

I've noticed that it does it more if I either drive like a grandma meaning very slow on the revs

Just a thought.

That could be the torque converter going out and back in to lockup. Maybe it is not going completely into lockup or taking too long and seems like it is slipping.

Start out a little faster than grandma and count the gears. When you are in 4th and the RPMs are around 3k or a little above let up a little on the throttle so you stop increasing speed. You may have to let up a little more and you should see the RPMs drop about 1k when the torque converter goes into lockup.

[cspurli2]

Okay thanks I'll try that on the way home today. 

 

[idosubaru]

3 hours ago, cspurli2 said:

It got hit on the passengers but I didn't even think to inspect the lines so I'll add that to the list. 

ATF related stuff is all drivers side and underneath the radiator, so it's unlikely.  But I'd definitely be tracing those lines to make sure, who knows if there was additional issue/damage/attention to areas other than the primary impact.  I've worked on, looked at, and rebuilt numerous totaled Subaru's and while the major impact is in one area, it's never a surprise to see weird additional minor things elsewhere on the vehicle from the incident itself or later attempts to repair, remove/transport vehicle on tow vehicles, storage, borrowing parts, vandalism, etc. 

The torque converter is a good item to look into - they're failure modes aren't well known and tricky to diagnose sometimes.  Are there any electro-mechanical issues like whirring or whining that aren't related to just RPM fluctuations?

[cspurli2]

7 hours ago, Rampage said:

Just a thought.

That could be the torque converter going out and back in to lockup. Maybe it is not going completely into lockup or taking too long and seems like it is slipping.

Start out a little faster than grandma and count the gears. When you are in 4th and the RPMs are around 3k or a little above let up a little on the throttle so you stop increasing speed. You may have to let up a little more and you should see the RPMs drop about 1k when the torque converter goes into lockup.

Just did it and it stutters on the way down at about 2k then continues. 

[cspurli2]

5 hours ago, idosubaru said:

ATF related stuff is all drivers side and underneath the radiator, so it's unlikely.  But I'd definitely be tracing those lines to make sure, who knows if there was additional issue/damage/attention to areas other than the primary impact.  I've worked on, looked at, and rebuilt numerous totaled Subaru's and while the major impact is in one area, it's never a surprise to see weird additional minor things elsewhere on the vehicle from the incident itself or later attempts to repair, remove/transport vehicle on tow vehicles, storage, borrowing parts, vandalism, etc. 

The torque converter is a good item to look into - they're failure modes aren't well known and tricky to diagnose sometimes.  Are there any electro-mechanical issues like whirring or whining that aren't related to just RPM fluctuations?

Nothing that seems out of the ordinary to me. Someone as I said the exhaust note will be alot louder when accelerating than what I think it should be. 

 

[GeneralDisorder]

Doesn't really matter since the rule with these is to replace them with a used one when they fail. So one day when it stops moving or when you get tired of dealing with the symptoms, swap the trans with a good used replacement with a warranty. There's nothing else that's going to solve that type of problem and rebuilding them is non-viable. 

GD

[cspurli2]

20 hours ago, idosubaru said:

ATF related stuff is all drivers side and underneath the radiator, so it's unlikely.  But I'd definitely be tracing those lines to make sure, who knows if there was additional issue/damage/attention to areas other than the primary impact.  I've worked on, looked at, and rebuilt numerous totaled Subaru's and while the major impact is in one area, it's never a surprise to see weird additional minor things elsewhere on the vehicle from the incident itself or later attempts to repair, remove/transport vehicle on tow vehicles, storage, borrowing parts, vandalism, etc. 

The torque converter is a good item to look into - they're failure modes aren't well known and tricky to diagnose sometimes.  Are there any electro-mechanical issues like whirring or whining that aren't related to just RPM fluctuations?

Nothing that seems out of the ordinary to me. Someone as I said the exhaust note will be alot louder when accelerating than what I think it should be. 

Thanks, that's basically what I was thinking. Also do any of you know if the plastic covers under the car are necessary? I find It a pain in the rump roast to take them on and off. But if they are I will leave them on. 

[idosubaru]

19 minutes ago, cspurli2 said:

Nothing that seems out of the ordinary to me. Someone as I said the exhaust note will be alot louder when accelerating than what I think it should be. 

Thanks, that's basically what I was thinking. Also do any of you know if the plastic covers under the car are necessary? I find It a pain in the rump roast to take them on and off. But if they are I will leave them on. 

The exhaust note description is odd to me. I would make sure what you’re feeling and describing are definitely transmission issues.  I’ve seen people get confused between what is an engine issue or transmission issue and engine issues can cause erratic shifting. I’ve had a number of people over the years who describe that they have a transmission issue and I end up repairing an engine issue. 

Under covers. No. They are routinely missing with age, I’m usually surprised to get a 10+ year old Subaru that still has them.  

[cspurli2]

I'll take a video of the rpms next time I'm driving to try and catch it.